Short for "run the gamut". Used for major accomplishments in savvy partying at multiple bars, find a glory parking spot, making a row of stop lights, eating a multi-course dinner and just all around getting it done.
"Dude, major 'gamrun' last night..."
"What'd you get into?"
"Started at Barrio, hit Anchovies & Olives, then Tavern Law, then El Camino and finished at Nectar Lounge. A huge 'gamrun'..."